The kilt is great for air travel, but I always wear a casual PV. velcro, no metal, slip on sandals, no dirk , airport security will hassle you whatever you wear...esp. US airports (never again), I'm sure they employ ex-prison guards!

OK so the pleats get a bit messed up! everyone looks pretty ragged after 20 hours flying!
But 20 hours in a seat, wouldn't be caught in trousers again.